Cover - shares	9 Months Ended
	Sep. 30, 2023	Nov. 01, 2023
Cover [Abstract]
Entity Registrant Name	Smith-Midland Corporation
Entity Central Index Key	0000924719
Document Type	10-Q
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Small Business	true
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Document Period End Date	Sep. 30, 2023
Entity Filer Category	Non-accelerated Filer
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2023
Entity Common Stock Shares Outstanding		5,257,413
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Entity File Number	1-13752
Entity Incorporation State Country Code	DE
Entity Tax Identification Number	54-1727060
Entity Address Address Line 1	5119 Catlett Road
Entity Address Address Line 2	P.O. Box 300
Entity Address City Or Town	Midland
Entity Address State Or Province	VA
Entity Address Postal Zip Code	22728
City Area Code	540
Local Phone Number	439-3266
Security 12b Title	Common Stock, $0.01 par value per share
Trading Symbol	SMID
Security Exchange Name	NASDAQ